From 5602452e4c9943a81c9cd049d10d37d3f137b0c0 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Thu, 3 Aug 2017 10:14:17 +0100 Subject: drm/i915: Use __sg_alloc_table_from_pages for userptr allocations With the addition of __sg_alloc_table_from_pages we can control the maximum coalescing size and eliminate a separate path for allocating backing store here. Similar to 871dfbd67d4e ("drm/i915: Allow compaction upto SWIOTLB max segment size") this enables more compact sg lists to be created and so has a beneficial effect on workloads with many and/or large objects of this class. v2: * Rename helper to i915_sg_segment_size and fix swiotlb override. * Commit message update. v3: * Actually include the swiotlb override fix. v4: * Regroup parameters a bit. (Chris Wilson) v5: * Rebase for swiotlb_max_segment. * Add DMA map failure handling as in abb0deacb5a6 ("drm/i915: Fallback to single PAGE_SIZE segments for DMA remapping"). v6: Handle swiotlb_max_segment() returning 1. (Joonas Lahtinen) v7: Rebase. v8: Commit spelling fix. Signed-off-by: Tvrtko Ursulin Cc: Chris Wilson Cc: linux-kernel@vger.kernel.org Reviewed-by: Chris Wilson Cc: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20170803091417.23677-1-tvrtko.ursulin@linux.intel.com --- drivers/gpu/drm/i915/i915_drv.h | 15 +++++++ drivers/gpu/drm/i915/i915_gem.c | 6 +-- drivers/gpu/drm/i915/i915_gem_userptr.c | 79 ++++++++++++--------------------- 3 files changed, 45 insertions(+), 55 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index c1aef3a1ceb9..2b08bbf608aa 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2828,6 +2828,21 @@ static inline struct scatterlist *__sg_next(struct scatterlist *sg) (((__iter).curr += PAGE_SIZE) < (__iter).max) || \ ((__iter) = __sgt_iter(__sg_next((__iter).sgp), false), 0)) +static inline unsigned int i915_sg_segment_size(void) +{ + unsigned int size = swiotlb_max_segment(); + + if (size == 0) + return SCATTERLIST_MAX_SEGMENT; + + size = rounddown(size, PAGE_SIZE); + /* swiotlb_max_segment_size can return 1 byte when it means one page. */ + if (size < PAGE_SIZE) + size = PAGE_SIZE; + + return size; +} + static inline const struct intel_device_info * intel_info(const struct drm_i915_private *dev_priv) { diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 1545a4ef09c4..4dffebae5601 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2303,7 +2303,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) struct sgt_iter sgt_iter; struct page *page; unsigned long last_pfn = 0; /* suppress gcc warning */ - unsigned int max_segment; + unsigned int max_segment = i915_sg_segment_size(); gfp_t noreclaim; int ret; @@ -2314,10 +2314,6 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) GEM_BUG_ON(obj->base.read_domains & I915_GEM_GPU_DOMAINS); GEM_BUG_ON(obj->base.write_domain & I915_GEM_GPU_DOMAINS); - max_segment = swiotlb_max_segment(); - if (!max_segment) - max_segment = rounddown(UINT_MAX, PAGE_SIZE); - st = kmalloc(sizeof(*st), GFP_KERNEL); if (st == NULL) return ERR_PTR(-ENOMEM); diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c index f152a38d7079..2ce078e8c763 100644 --- a/drivers/gpu/drm/i915/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/i915_gem_userptr.c @@ -399,64 +399,42 @@ struct get_pages_work { struct task_struct *task; }; -#if IS_ENABLED(CONFIG_SWIOTLB) -#define swiotlb_active() swiotlb_nr_tbl() -#else -#define swiotlb_active() 0 -#endif - -static int -st_set_pages(struct sg_table **st, struct page **pvec, int num_pages) -{ - struct scatterlist *sg; - int ret, n; - - *st = kmalloc(sizeof(**st), GFP_KERNEL); - if (*st == NULL) - return -ENOMEM; - - if (swiotlb_active()) { - ret = sg_alloc_table(*st, num_pages, GFP_KERNEL); - if (ret) - goto err; - - for_each_sg((*st)->sgl, sg, num_pages, n) - sg_set_page(sg, pvec[n], PAGE_SIZE, 0); - } else { - ret = sg_alloc_table_from_pages(*st, pvec, num_pages, - 0, num_pages << PAGE_SHIFT, - GFP_KERNEL); - if (ret) - goto err; - } - - return 0; - -err: - kfree(*st); - *st = NULL; - return ret; -} - static struct sg_table * -__i915_gem_userptr_set_pages(struct drm_i915_gem_object *obj, - struct page **pvec, int num_pages) +__i915_gem_userptr_alloc_pages(struct drm_i915_gem_object *obj, + struct page **pvec, int num_pages) { - struct sg_table *pages; + unsigned int max_segment = i915_sg_segment_size(); + struct sg_table *st; int ret; - ret = st_set_pages(&pages, pvec, num_pages); - if (ret) + st = kmalloc(sizeof(*st), GFP_KERNEL); + if (!st) + return ERR_PTR(-ENOMEM); + +alloc_table: + ret = __sg_alloc_table_from_pages(st, pvec, num_pages, + 0, num_pages << PAGE_SHIFT, + max_segment, + GFP_KERNEL); + if (ret) { + kfree(st); return ERR_PTR(ret); + } - ret = i915_gem_gtt_prepare_pages(obj, pages); + ret = i915_gem_gtt_prepare_pages(obj, st); if (ret) { - sg_free_table(pages); - kfree(pages); + sg_free_table(st); + + if (max_segment > PAGE_SIZE) { + max_segment = PAGE_SIZE; + goto alloc_table; + } + + kfree(st); return ERR_PTR(ret); } - return pages; + return st; } static int @@ -540,7 +518,8 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work) struct sg_table *pages = ERR_PTR(ret); if (pinned == npages) { - pages = __i915_gem_userptr_set_pages(obj, pvec, npages); + pages = __i915_gem_userptr_alloc_pages(obj, pvec, + npages); if (!IS_ERR(pages)) { __i915_gem_object_set_pages(obj, pages); pinned = 0; @@ -661,7 +640,7 @@ i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj) pages = __i915_gem_userptr_get_pages_schedule(obj); active = pages == ERR_PTR(-EAGAIN); } else { - pages = __i915_gem_userptr_set_pages(obj, pvec, num_pages); + pages = __i915_gem_userptr_alloc_pages(obj, pvec, num_pages); active = !IS_ERR(pages); } if (active) -- cgit v1.2.3-59-g8ed1b